This invention relates in general to locking devices and, more particularly, to a detent latch or lock for a vehicle transmission gear shifter. More specifically, but without restriction to the particular use which is shown and described, this invention relates to a pivoting detent latch for securing a transmission gear shift lever in a desired position.
In vehicles such as construction machinery or earth-moving equipment, a transmission is utilized to couple the output of a vehicle engine to the drive mechanism. The transmission has a gear shift lever through which the vehicle operator can manually shift the transmission into the gear desired.
Generally, there are plurality of gear positions into which the transmission can be shifted, i.e., forward, reverse or neutral, in order to effect vehicle operation. The gear shift lever, which is freely movable through the plurality of gear positions, is utilized to shift the transmission among these gear positions.
When the vehicle is not in use, or not being driven, the shift lever should be placed in the gear position corresponding to neutral so that the transmission is not engaged. However, due to the movability of the shift lever, there can be no adequate assurances that the gear shift lever will remain in the neutral position once it is positioned there. For example, if the vehicle operator puts the shift lever of the vehicle in the neutral position and leaves the vehicle engine running, the vibrations of the vehicle could cause the shift lever to accidentally be jarred into a driving gear position. Such accidental shifting into forward or reverse, would cause the vehicle to move of its own accord, potentially causing considerable property damage or bodily injury to those in close proximity.
In order to prevent damage to the vehicle, property damage or bodily injury that could result from the shift lever being accidentally or unintentionally jarred into a drive position, it is desirable to provide a safety device that will securely hold the gear shift lever in a neutral position. Such a device must function so that when the gear shift lever is positioned in neutral by the vehicle operator, it will remain in that position until the vehicle operator desires to engage one of the drive gear positions in order to move the vehicle.
The present invention, therefore, provides a positive detent latch or lock that utilizes a locking arm with a latch member whereby the member is manually rotated to contact the locking arm and move the gear shift lever into engagement with stop means. The shift lever is then fixedly secured in the neutral position, and can only be moved from neutral when the vehicle operator manually rotates the latch member in reverse direction, thereby allowing free movement of the gear shift lever.
The prior art includes various devices for locking a gear shift lever in the neutral position. One such device is shown in U.S. Pat. No. 4,163,398. This patent discloses a pair of levers located on opposite sides of a shift lever and selectively operable to hold the shift lever in the neutral position. The prior art further includes various locks, such as a tool box lock, which are movable between a first position wherein an associated member is free to move and a second position wherein the associated member is locked in position.